Targeting Diabetes Mellitus through Phytochemicals: A Systematic Overview of Plant-Derived Bioactives, Pathophysiological Mechanisms and Clinical Implications

Diabetes mellitus (DM) is a severe metabolic disorder characterised by persistently high blood glucose levels, which arise due to inadequate insulin secretion, dysfunctional insulin activity, or a combination of these factors. While pharmacological treatments have advanced significantly, conventional therapies often fail to deliver optimal results due to their broad-spectrum approach. This challenge has led to growing interest in phytochemicals, naturally occurring bioactive compounds from plants, as alternative or complementary strategies for diabetes management. Various phytochemicals, including polyphenols, flavonoids, alkaloids, and terpenoids, have demonstrated notable antidiabetic properties. These compounds improve insulin sensitivity, promote better glucose regulation, reduce oxidative stress, and lower inflammation. Their mechanisms of action involve enhancing β-cell function, inhibiting α-glucosidase enzymes, and promoting lipid homeostasis. Evidence from both preclinical and clinical studies supports their therapeutic potential and safety profile. Nevertheless, further well-structured clinical trials are essential to establish appropriate dosages, long-term safety, and efficacy. This review emphasises the promising role of phytochemicals in diabetes management, underscoring their value in enhancing glycaemic control and mitigating complications.